ta (4) conj., said to be a reducted form of tá "then", used "before each new item in a series or list"; "if as often in English the equivalent of and was omitted, and placed only before a final item [e.g. Tom, Dick, and Harriet], this would in Quenya represent a discontinuity, and what followed after ta would be an addition of something overlooked or less important". (PE17:70) Hence the use of arta (ar ta, "and ta") for "et cetera"; in older language ta ta or just ta.
Quenya
tá
adverb. then, then, [ᴹQ.] at that time [past]
ta
then
tá
high
tá 2) adj. "high" (LT1:264; there spelt tâ. This is hardly a valid word in Tolkien's later Quenya, but cf. tára "lofty".)
tá
then
tá 1) adv. "then" (VT49:11). Cf. ta #4.
tána
high, lofty, noble
tána (meaning unclear, probably adj. "high, lofty, noble") (TĀ/TA3). Compare tára.
tai
then
tai (3) adv. "then", also tá (which form may be preferred because tai has other meanings as well) (VT49:33)
tar-
affix. high, high; [ᴹQ.] king or queen (in compounds)
tai
1lE adverb. then
arata
high, lofty, noble
arata adj. "high, lofty, noble" (PE17:49, 186). Also used as a a noun with nominal pl. form Aratar "the Supreme", the chief Valar, translation of the foreign word Máhani adopted and adapted from Valarin (WJ:402). Aratarya "her sublimity"; Varda Aratarya "Varda the lofty, Varda in her sublimity" (WJ:369). In one source, Aratar is translated as a singular: "High One" (PE17:186)
arata
high, lofty, noble
arata adj. "high, lofty, noble" (PE17:49, 186). Also used as a a noun with nominal pl. form Aratar "the Supreme", the chief Valar, translation of the foreign word Máhani adopted and adapted from Valarin (WJ:402). Aratarya "her sublimity"; Varda Aratarya "Varda the lofty, Varda in her sublimity" (WJ:369). In one source, Aratar is translated as a singular: "High One" (PE17:186)
halda
adjective. high, tall
san
then
san (1) adv. "then" (MC:216; also twice in Narqelion), a "Qenya" term apparently replaced by tá in Tolkiens later conception. In his later Quenya, san would be the dative form of sa "it", hence "for it; to it".
or
preposition. above, above, [ᴱQ.] upon; on
A word for “then” appearing in a list of demonstratives from 1968, a vowel-lengthened form of ta “that” (VT49/11). It reappeared in some notes from 1969 alongside a variant tai (VT49/33). ᴹQ. tá “then, at that time (past now)” appeared in Demonstrative, Relative, and Correlative Stems (DRC) from 1948, where Tolkien indicated it was specifically used to refer to the past (PE23/109), as opposed to ᴹQ. en “then” referring to the future.